Pedal-crank for bicycles



(No Model.)

W. 0.. SMITH. PEDAL CRANK FOR BIGYGLES.

No. 510,620. Patented Dec. 12, 1893.

NlTED STATES:

PATENT union,

\VILLIAM 0. SMITH, OF GOSHEN, INDIANA.

PEDAL-CRANK FOR BICYCLES.

SPECIFICATION forming part of Letters Patent No. 510,620, dated December12, 1893.

Application filed February 23, 1893- Serial No. 463,518. (No model.)

T!) on whom it may concern:

Be it known that I, WILLIAM CHURCH SMITH, of Goshen, in the county ofElkhart and State of Indiana, have invented certain new and usefulImprovements in Pedal- Oranks for Bicycles, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings, and to the letters of reference marked thereon.

Heretofore considerable diificulty has been experienced by bicyclists inobtaining a pedal crank, which, when secured on the pedal-shaft wouldremain rigidly secured thereon, and yet, when for purposes of repair itwas desirable to remove it could be easily removed without injuring thethread on the end of the wedge to such extent that it was very difficultto get the nut on the same again.

The object of my invention is to overcome the above objections, and, atthe same time, provide a strong and durable crank connection with thepedal-shaft; substantially as hereinafter fully described, and asillustrated in the drawings, in which Figure 1, is an edge elevation ofmy improved pedal crank, secured to the broken off contiguous end of thepedal-shaft. Fig. 2, is a side elevation of the same, and Fig. 3, is avertical section through the upper connecting end of the said crank,taken on dotted line 3, 3, Fig. 1.

In the drawings A represents the pedalcrank, the sweep of which may beconstructed "9 as to be at right angles to the pedal-shaft is, oroblique thereto, as shown in the drawings, or otherwise, and which hassecured to its outer end any suitable form of pedal 0 in the usualmanner. The end of the pedalshaft B, to which the crank is secured, isprovided with a suitable transverse recess a, the floor of which isperfectly straight as a chord connecting the ends of a segment, andaffords a seat for the flattened beveled side of the wedge b. Thisrecess a is located in the upper side of the shaft B, when the crank isin the vertical position shown in the drawings, and the wedge is seatedin a circular chamber c, which commences in a suitable stub d projectinglaterally to one side of the boss D of the crank, and extends a suitabledistance into the opposite side of said boss, as shown.

The entrance to chamber 0 is provided with a female screw, and a shortheadless screw e is, after the wedge has been inserted into chamber 0,screwed into the mouth of the same so as to force the wedge home. Whenthis screw is removed the wedge can easily be driven out by insertingany kind of a suitable instrument through the passage f (which forms acontinuation of less diameter than said chamber, and opens on the sideof the boss opposite the mouth of the same) and hammering against theadvance end of said wedge.

To be more exact about the location of the wedge, I would state that animaginary line drawn longitudinally, and centrally through chamber 0 andpassage f, is, preferably, not at right angles to the plane of length ofthe the crank, but at an angle of about twenty degress or so, to suchright angle.

As hereinbefore described I have a construction whereby it is impossiblefor the pressure on the wedge to afiect the connection between the crankA and shaft B to its detriment. The screw e being headless, and enteringwell into the chamber when driving the wedge home is not affected byexternal agencies, and the direct pressure of the wedge against itcannot cause it to unscrew. Oonsequently, the connection must remain asoriginally made.

While what has been described heretofore could be used by itself, and avery perfect connection be thus obtained, I prefer to make a yetstronger connection whereby the possibility of the crank becoming looseon the shaft is precluded. This consists of providing the boss D with adownwardly extending lip F on that side adjacent to the mouth of thechamber 0, instead of making the boss a solid ring surrounding theshaft. Thus lip F is obtained by slitting the crank from the edge to theshaft opening in the boss thereof in an almost longitudinal direction,as shown in Fig. 2, and it is secured to the main body of the crank bymeans of the bolt G, which extends laterally through said lip and crankand is tightened by a suitable nut g. Now, when the wedge is driven homeby means of the screw e by tightening the bolt G, any possible loosenesswhich might have been permi tted to exist by not driving thewedge homesufliciently can be taken up. By using the lip F, and bolt G, I alsoobtain a means which makes my improved crank connection practicallyadjustable on the end of the pedalshaft of any bicycle, because I amthereby permitted to embrace the circumference of the same, which itwill be borne in mind varies very little in diameter. Yet even a slightvariation in diameter is enough to make a crank having the solidring-shaped boss which would fit the shaft of one bicycle, not fit theshaft of the other.

What I claim as new is- 1. The combination in a vehicle with a shaft,having a transverse recess therein near 1ts extremity, of a pedal crankhaving a transverse chamber in the rounded end of its boss, the entranceto which is provided With a fe male screw, a wedge seated in saidchamber, a short screw entering the month of the same, and a pedal onthe free end of said crank.

2. The combination in a vehicle with a shaft, having a transverse recesstherein near its extremity, of a crank having a transverse chamber inthe rounded end of its boss, the entrance to which is screw threaded,and which has a passage leading from the opposite end thereof inalignment therewith, a wedge seated in said chamber a short screwentering the mouth of the same, and a pedal on the free end of saidcrank, as set forth.

3. The combination in a vehicle with a shaft having a transverse recesstherein near its end, of a pedal having a transverse chamber in therounded end of its boss, the entrance to which is screw-threaded, awedge within said chamber seated in said recess, a short screw enteringthe mouth of said chamber, a boltG and nut 9; said pedal havinga lipmade by slitting the same almost longitudinally from its edge to theshaft opening, through which said bolt passes transversely to clamp itto the main body of said crank, as set forth.

WILLIAM 0. SMITH.

Witnesses:

CHAS. W. MILLER, R. J. JAOKER.

